| Popis: |
The Integrated Management Plan for the Barents Sea and Lofoten area (Arctic area) reports that human intervention and activities shall not harm the function, structure, productivity or dynamics of the ecosystem. The precautionary principle is currently the guiding principle applied in the Norwegian Barents Sea based on the assumption that Arctic areas host a fragile and sensitive ecosystem. The industry proposed a zero physical discharges regime in this area which has been strictly implemented in the regulation on the assumption that this will provide the best environmental practice. The precautionary principle and zero discharge are therefore presently applied to E&P discharges rather than using a scientifically based approach. TOTAL E&P NORGE together with Eni E&P Division and its subsidiary Eni Norge have joined forces to establish a research project, BIOSEA, designed to build scientific knowledge on Arctic ecosystem sensitivity towards regular E&P discharges based upon experience (and results) from similar research projects for the North Sea temperate ecosystem. The project objective is to generate a qualified set of data for assessing the impact of produced water and dispersed oil discharges on Arctic marine organisms that can contribute to a scientific based approach for defining effect thresholds. Larvae, juveniles and adults of Arctic species selected for their key position in the ecosystem have been exposed to realistic field concentration of produced water. The experiments were designed to assess short term response and long term biological effects after one month to several months of exposure. Exposures were run both to validate monitoring tools and to establish no effect concentration levels for produced water discharges in Arctic waters. A series of no observable effect concentrations (NOEC) and lowest observed effect concentrations (LOEC) have been established throughout the project for cod, northern shrimps and Icelandic scallops at Arctic conditions with a Barents sea crude oil. These results were compared to available data for the same or similar species exposed to North Sea conditions and a North Sea crude oil. From this comparison, it is concluded that the species tested do not present a higher sensitivity to dispersed crude oil at Arctic compared to North Sea conditions. As compared to the threshold level concentration measured for the early life stages, most of the biomarkers measured in adults showed no responses at corresponding concentrations. This comparison shows that the sensitivity of some of the biomarkers commonly used in field monitoring are not high enough to serve as early warning for effects at the most vulnerable life stage in these organisms. These results underline the importance of carrying out tests with early life stages and refining the set of biomarkers used in field monitoring. These data will be supplemented with tests on additional Arctic species. It is by building a representative dataset and integrating this into an appropriate ecological risk assessment model that a realistic assessment of environmental impact linked to oil and gas industry will be achieved. |
